Urinary incontinence is a symptom wherein discharge of urine via bladder and urethra cannot be done upon one's wish.
Many years have passed since therapy for aged people is to be done on an improved basis due to a significant prolongation of average human life while the frequency of occurrence of urinary incontinence of aged people who are always in bed is presumed to be about 75%. Development of remedies for urinary incontinence in order to overcome the above has been a brisk demand by the people who take care of and assist them.
At present, there has been a remarkable participation of ladies in public society. Urinary incontinence is often observed in ladies, particularly who experienced pregnancy and is a cause of anxiety for them in participating in public affairs and there is an increasing demand for remedies for urinary incontinence.
Conventional remedies for urinary incontinence such as flavoxate aim a decrease in the frequency of urinary incontinence. They act on bladder and relax it whereupon urinary incontinence is expected to alleviate.
Another type of drugs which prevent urinary incontinence based upon different action mechanism is .alpha..sub.1 -receptor stimulants. They accelerate the contracting action of smooth muscle of urethra for alleviating the symptom. For example, midodrine (a hypertensive agent) and norephedrine (antitussive agent) have been used mostly outside Japan.
In Examined Japanese Publications 15101/66, 06169/67 and 19500/70, there is a disclosure that the compounds having the following general formula and a part of them exhibit wide and useful pharmacological action suitable as antiinflammatory agents for preventing anaphylaxis and also as hypertensive agents for blood vessel, hypotensive agents for blood vessel, analgesics, bronchodilators, .alpha.-receptor stimulants, .alpha.-receptor blocking agents, .beta.-receptor stimulants, .beta.-receptor blocking agent and relaxants for smooth muscle (like papaverine). ##STR8## wherein X is hydrogen, hydroxy, amino, lower alkoxy, benzyloxy, halogen/methyl or R.sup.2 SO.sub.2 NH--; R.sup.1 and R.sup.2 are lower alkyl, phenyl or tolyl; R.sup.3 is hydrogen or methyl; Z is C.dbd.O or CHOH; R.sup.4 in --NR.sup.5 (R.sup.4 is hydrogen, lower alkyl or benzyl; R.sup.5 is hydrogen, lower alkyl, aralkyl, ring-substituted aralkyl, aryloxyalkyl or ring-substituted aryloxyalkyl (wherein said ring-substituent is hydroxyl, methoxy or methylenedioxy; said lower alkyl and lower alkoxy have 4 or less carbon atoms; and said alkyl, ring-substituted aralkyl and ring-substituted aryloxyalkyl have 10 or less carbon atoms); and R.sup.4 and R.sup.5 may form pyrrolidino, morpholino or piperidino together with nitrogen atom whereby the structure stands for sulfonanilide derivative.
In addition, Examined Japanese Publication (15101/66; left column on page 12) discloses 2-fluoro-5-(2-methylamino-1-hydroxyethyl)methanesulfonanilide which is one of the compounds belonging to the above-given general formula (note: terms etc are the same as those disclosed in said patent). Said compound has the following structural formula (X): ##STR9##
However, the pharmacological effect of the compounds disclosed in the above-given prior art literatures is a common contracting action to smooth muscle only. Accordingly, it is difficult to develop the pharmaceuticals which are helpful for the therapy of urinary incontinence.